The present invention is directed to the field of culturing plants, and more particularly to the field of culturing plants in arid environments.
A major obstacle in the path of increasing the world's food supply is the transformation of arid regions into areas suitable for agriculture. Effective development of such regions depends upon the solution to four problems. First, an adequate, dependable water supply must be assured. Although deep wells and desalinization have ameliorated this problem, these methods are expensive, and steps must be taken to utilize what water becomes available at the maximum possible efficiency.
Second, evaporation of available water must be minimized. Arid climates by definition include the elements conducive to rapid evaporation of whatever water is provided. Methods that depend upon irrigation canals, for example, allow an appreciable portion of the water to be evaporated before it can be put to use.
Third, wind damage must be prevented. Arid areas are characterized by the prevalence of strong winds. Not only do such winds increase the hazards of evaporation discussed previously, but also they can cause physical damage to the plants, particularly in early stages of growth.
Fourth, the accumulation of salts in the soil must be controlled. Regardless of the method used to control evaporation, that process will proceed at a higher rate than in temperate zones. Therefore, salts will tend to build up in the soil at a more rapid rate that would be found in other environmental conditions, with the result that the soil can rapidly become unsuitable to agriculture.
The prior art generally has failed to address the last three problems in any effective manner. Irrigation systems now in general use include not only canal-based systems, but also central-pivot systems in which irrigation pipes are rotated in circular patterns around a source pipe, and drip systems in which lines of irrigation piping supply water at a slow rate to plant areas. Inasmuch as all of these systems supply water at the surface level, the problems of evaporation and salt accumulation clearly are not dealt with. Further, application of water to the ground surface causes the soil to become soft, weakening the plants' ability to withstand wind forces.
Therefore, a clear need exists to provide improved methods and apparatus for plant culture in arid environments.